'Whispering campaign' against Filkin

A whispering campaign to discredit Elizabeth Filkin, the parliamentary standards commissioner, and ensure she failed to be reappointed to her post was mounted by supporters of the former Foreign Office minister Keith Vaz, the Guardian has learned.

Friends of Mr Vaz, who is still under investigation by Ms Filkin for his links with the controversial Hinduja brothers, were behind a spate of false allegations of "conflict of interest" aimed at the commissioner.

They included claims that

· Her husband, Michael Honey, had once sacked Mr Vaz.

· She was prejudiced because she once sat on a committee with Sir Peter Soulsby, one of the principal Vaz accusers.

· She had an interest in the building society to whom former minister Peter Mandelson had failed to reveal on his mortgage application his £373,000 loan from Geoffrey Robinson.

The "conflict of interest" disclosures surfaced in spring just as the House of Commons Commission - a shadowy group of MPs whose proceedings are concealed from the rest of parliament - debated whether to refuse Ms Filkin a second term.

The whispers were aimed at showing that the independent commissioner was not conducting fair investigations into the conduct of MPs.

None of the allegations stand up to scrutiny. Ms Filkin had resigned her outside directorships, including the Britannia Building Society, before she was appointed commissioner.

The assertion that she might be prejudiced because she had sat on an audit commission sub-committee with Sir Peter - openly put by Geoffrey Bindman, Mr Vaz's solicitor - was found by MPs to be absurd.

The claim is also strongly disputed that she should have disclosed that her husband, Michael Honey, as chief executive of Liberal Democrat- controlled Richmond council when Mr Vaz was a junior solicitor there in 1982, was responsible for him being removed from his job.

Mr Vaz declined to comment on the origins of the whispering campaign.

Ms Filkin, for her part, refuses to discuss the nature of the ongoing investigation into him. The commission decision not to renew her contract means it may peter out in February.

Mr Vaz has already been found to have privately recommended a solicitor, Sarosh Zaiwalla, for an honour without declaring financial links. He stepped down as a minister, but retained his Leicester seat in the general election.